Ascertainment and collection of patients for genetic studies of schizophrenia and neuroleptic malignant syndrome are described in the report of Dr. Gershon (Outpatient Clinic for Genetic and Pharmacologic Studies of Affective Disorders, project 01 MH 00086-22 CNG). 1. Genetic mapping of schizophrenia: we are performing systematic mapping on 73 families with 104 affected sib-pairs [(n*n-1)/2]. Genotyping system has been shift in 1997 from manual radioactive methods to semiautomatic methods (ABI Automated sequencers). a. First pass with 114 markers of Weber map 6.2 has been completed. b. Areas with evidence for linkage in other series of schizophrenia in chromosomes 18, 5, 2 and 10 have been genotyped (high resolution coverage of these areas) (40 markers). c. Chromosome 6 has been finished last year in our pedigrees with results of suggestive linkage in 6q26q13 which have been confirmed in an additional sample (NIMH Genetics Initiative collection). 2. Quantitative trait loci mapping of prepulse inhibition in the mouse orientation: 1- We are genotyping the top 5% and the bottom 5% PPI scoring mice with genetic markers covering the mouse genome at a density of approximately 20 cM on 96 animals with an ABI sequencer. 3. Genetic linkage study of male homosexual orientation: we are currently examining genetic markers in the X chromosome in 54 sibling pairs.